ZIPskinny is an amazing research site. All you have to do is type in a zip code for anywhere in the United States, and you immediately get information from the 2000 Census, along with a map of the area.
Not only that, but you can also compare the data with neighboring zip codes.
My English Language Learner classes usually do demographic studies, and Intermediate level students should be able to access this site.
I’ve placed the link on my Examples of Student Work page under Student Neighborhood Maps. It may seem like a strange place to put it, but that’s where I’ve put another site they use to create neighborhood demographic maps. So, I figure, for now that’s a good place for this link, too.